Join us for an unforgettable evening under the stars at Ronald W. Caspers Wilderness Park! The Space Ranger Program and Starr Party, hosted by OC Parks staff and volunteers, offer fun and learning for families and space enthusiasts alike. No camping required—just bring your curiosity!

Space Ranger Program
Kick off your night with the Space Ranger Program, a one-hour event starting one hour before sundown at the Nature Center. This engaging experience features fun activities and space-related talks, perfect for all ages. Visitors are welcome to attend the Space Ranger Program independently of the Starr Party. Earn “Space Ranger” rewards by attending multiple programs and reaching exciting milestones along your cosmic journey!

Starr Party
For over 25 years, Caspers Park has been a hub for stargazing, earning California’s first “Star Park” designation in 2013. Once the sun sets, the Starr Party begins! Join us outdoors to marvel at the stars and explore the cosmos through telescopes provided by volunteers and OC Parks staff. Telescopes will be available until 9 PM, and visitors may leave whenever they choose.

What to Expect
Expert Guidance: Volunteers will share fascinating insights about the night sky and celestial objects.
Family-Friendly Fun: Activities designed for visitors of all ages.
Optional Gear: Feel free to bring binoculars, telescopes, or cameras, but no equipment is necessary to enjoy the event!

Event Details
Location: Ronald W. Caspers Wilderness Park Nature Center
Parking: Available in the lower lot near the Nature Center.
Admission: A vehicle entry fee applies for those without a camping reservation. The event itself is free.

Weather Notice
This event is weather-dependent. In case of inclement weather, parts of the program may be affected. For updates, call (949) 923-2210 on the day of the event to confirm if we’re clear for takeoff!

Join us Sunday morning in OC Parks’ Irvine Ranch Open Space for a fitness-focused hike on the Hicks Haul Road, West Loma and Shoestring trails in Limestone Canyon. Hikers will enjoy wonderful views and a panoramic overview of Orange County. The hike starts at Hicks Haul Road staging area and will cover a distance of 8.5 miles, about 5 miles of the hike is on paved surface and rest on trails. Participants are expected to hike close to 3 miles per hour and come prepared with closed toe hiking boots or shoes, water, trail snacks, sunscreen, hat, day pack or fanny pack, and any other necessary equipment or supplies you might need to keep you safe on this hike.

Experience the serenity of Bommer Canyon during this moderate-paced hike in the Irvine Open Space Preserve. We’ll experience mature coastal sage scrub and fantastic views overlooking the city of Irvine and the hillsides to the north. This hike is just over 3 miles and includes 700 feet of total climbing elevation with several very steep inclines. The steepest section ascends 300 feet in a quarter-mile. Participants must be in good physical condition.

Enjoy miles of lush oak studded canyons, fascinating rock formations and sweeping views from the Overlook Trail in the tranquility of the Weir Canyon back country, part of OC Parks’ Irvine Ranch Open Space. On a clear day we’ll be rewarded with glorious views of the San Gabriel and Santa Ana mountains. This is a fitness hike and features an 1800 ft accumulated elevation gain. There are multiple steep climbs and steep descents. Please make sure you are in excellent physical condition! You must be able to hike uphill at an average pace of 3 mph without stopping. A backpack and water are required. Please bring snack, sun screen, hat and wear sturdy closed-toe shoes.

Experienced mountain bikers can explore one of the most rugged and remote areas of OC Parks’ Irvine Ranch Open Space from the trails of Fremont Canyon Nature Preserve on this moderate-paced ride through Fremont, Blind, and Weir Canyons. Fremont Canyon remains one of the most wild places in Orange County, with a diversity of rare plants and animals. This ride includes natural trail hazards such as sand, tree roots, ruts, and exposed rocks.  PLEASE NOTE: there are multiple very steep climbs, with an approximate elevation gain of 2,000 feet over 15 miles.  This hard ride is for adult-only riders in excellent physical condition who will be rewarded with the beautiful vistas. Motorized recreation vehicles of any class or type are not permitted for recreational use.

Join Mile Square Regional Park staff and volunteers in enhancing the Nature Area habitat for local wildlife. Activities may include non-native plant removal, planting natives, watering, trash cleanup, and Butterfly Garden maintenance.

No experience is necessary; please bring a hat, sunscreen, snacks, water, wear closed toe shoes and a long sleeve shirt is recommended. Tools are provided. Please arrive on time, as work will begin promptly at 9 am.

Please note, this is a weekly reoccurring activity and space is limited. Please park in Parking Lot H and walk to the volunteer shed west of the overflow lot entrance.

• Space is limited and pre-registration is required.
• Minors ages 16 and younger must have a legal guardian present at all times.
• Rain or heat advisories cancel the event.

For families and children ages 12 and up who would like to join IRC-certified volunteers in OC Parks’ Irvine Ranch Open Space on a longer, slow-paced, family-oriented ride through sycamores, oaks, and habitat native to California. The route takes us to The Sinks, Orange County’s own “Grand Canyon.” Along the way, we will stop and talk about the local habitat, and hope to see some of our local native animals and raptors. The ride is an 8-9 miles with 400-800 feet of elevation gain that may require hike-a‐bike for some riders. Motorized recreation vehicles of any class or type are not permitted for recreational use.

Come enjoy a scenic evening cardio hike in the remote Fremont Canyon Nature Preserve, part of OCParks’ Irvine Ranch Open Space. Our hike climbs steeply from the mouth of Fremont Canyon along the Lakeview Trail overlooking Irvine Lake. Upon reaching our turnaround point, we’ll head back the same way, descending to our starting point. This challenging hike involves steep climbs and an 1100’ elevation gain but the rewards are sweeping views of Fremont at sunset. Please arrive 15 minutes early and come prepared with a sturdy pack, water, closed-toe hiking shoes or boots, sunscreen, first aid, and all other supplies to keep you safe and healthy on the trail.

Birds are among the most colorful and entertaining forms of wildlife on the Irvine Ranch Natural Landmarks. Bring your binoculars and join us on a slow/medium paced walk in OC Parks’ Limestone Canyon, as we search for resident and visiting birds of the local coastal sage scrub, oak woodland, riparian, and grassland habitats. We will discuss the diverse features of the birds we observe and how they match the season, their habitat and lifestyle. We will travel mostly on ranch roads, usually without shade. Beginners to advanced bird enthusiasts are welcome. Please wear sturdy shoes suitable for hiking and bring water, along with sun protection such as a hat and sunscreen. Bring a small birding field guide if you have one. A few binoculars will be available to borrow.

Come start your week with us on our Super Treks in the Landmarks. Join us as we explore Weir Canyon, part of OC Parks’ Irvine Ranch Open Space. We will hike up over Rifle Range and continue to the Overlook Trail where we will be rewarded with sweeping views of the Irvine Ranch Natural Landmarks and more distant views of the Palos Verdes Peninsula, Los Angeles Basin, and Cleveland National Forest. We will return through a beautiful oak woodland. Please wear hiking shoes/boots and bring water, a trail snack, sunscreen, hat, and any other necessary equipment to keep you safe on the trail. Participants must be able to hike 9+ miles with an accumulated elevation gain of 1800 feet at an average moving rate of 3 miles per hour.

Take a leisurely equestrian ride through beautiful Baker Canyon in the Black Star Wilderness Area, home of oak woodlands, grasslands, and coastal sage scrub.  View evidence of the old ranch days when cattle once roamed the area and see some of the wildflowers that are native to our area.  You will gain amazing views of the local canyons and Irvine Lake.

Be prepared to experience the beauty and wonder of Weir Canyon, part of OC Parks’ Irvine Ranch Open Space, steeped in history and lore, on this morning equestrian ride. The ride will travel through Weir Canyon, where the trail weaves its way through a beautiful oak woodland inhabited by deer, coyote, bobcat, and many different birds. You will travel the route of the Butterfield Stage and see a monument dedicated to the Mexican ox cart drivers. If time permits, we will climb to the Two Tower vista point to look at distant views. This ride travels on wide trails with several easy to moderate climbs. Equestrians who have trail riding experience and their own fit and able horse are welcome. You will need to transport your horse to the staging area. Owners of unshod horses, please note that footing will include areas of gravel and distances over asphalt pavement. Please bring water on the ride.

Join us every Monday night for a fitness-focused hike on the paved Hicks Haul Road in the Irvine Open Space Preserve. During the spring, summer and fall, hikers will enjoy wonderful sunset views and a panoramic overview of Orange County. This hike travels about 3.5 miles, up to the top of Loma Ridge and back down. The hike is conducted at about 3-3.5 miles per hour, but you may travel a bit faster or slower, at a walk, run, or jog depending on your comfort level. Most participants finish the route in about 1 hour. Because of the paved surface of the road, you may wear regular running or walking shoes. Trail shoes are fine, but not required. Please bring adequate water.

Ready for a workout? Forget the gym for the day and head outside! Join us for an exhilarating morning fitness hike on the paved Hicks Haul Road in OC Parks’ Irvine Ranch Open Space. This hike allows you to choose between a 3, 6, or 8 mile route, all of which are conducted at the speed of about 3.0 to 3.5 miles per hour. The footing on the asphalt paved road is smoother than dirt roads and single track trails normally found in Limestone Canyon Nature Preserve, but is beginning to show its age with cracks, crevices and an occasional dip. Otherwise, the terrain is smooth, so this is a great walk for anyone who wants a “wilderness experience” without getting dirty! The 6 and 8 mile routes experience two fairly steep ascents and descents. The 3 mile route takes you to the top of Loma Ridge and back down. Along the way, you will have sweeping views of much of Orange County and the Santa Ana Mountains. Various animals, like hawks, deer, and lizards are also frequently seen in this area.

Join us on a slow-paced hike along the back-country ridges and valleys of Weir Canyon, part of OCParks’ Irvine Ranch Open Space. We’ll travel on rough old ranch roads passing by woodlands of majestic oak trees and expanses of Coastal Sage Scrub and enjoy wonderful vistas. Total round-trip distance is 5 miles with an elevation gain of 500 feet at an average moving rate of 2.0-2.5 miles per hour. Some of the hills are strenuous and we will take breaks as needed. Participants should be in good hiking condition and have previously completed a similar distance hike. Please come prepared with a backpack, plenty of water (at least 1 liter), snacks, sturdy closed-toe hiking shoes or boots, sunscreen, first aid kit, and all other supplies to keep you safe and healthy on the trail. Each hiker must carry their own water and supplies. Under-prepared participants may be denied access to the event.

Spend your morning helping to remove weeds and rebuild berms within the butterfly habitat islands in Limestone. With your help we will be able to maintain “islands” of host and nectar plants for butterflies in decline in Limestone Canyon. You will be transported from via a safari style truck from butterfly island to butterfly island through a beautiful oak woodland.

Join Ross, local nature and trail expert, at the Library of the Canyons as he shares opportunities for family-friendly hiking adventures! Learn about local trails, hiking tips, and canyon critters. Decorate a water bottle for your next outdoor experience! Sponsored by Irvine Ranch Conservancy.

Learn more at ocpl.org/summer-reading-2025

Enjoy an evening hike through stunning rock formations and fragrant native plants as you listen to the sounds of nature. During this hike in the Irvine Ranch Open Space, you may travel at various hiking speeds based on your comfort level.  This out-and-back program travels 3.5 miles round trip up to scenic Loma Ridge and back down. Please bring a red-tinted flashlight as the return portion of the hike may be after sunset.

Join OC Parks for an interpretive bike ride around Upper Newport Bay! Participants will have the opportunity to get their heart rate up and pedal around the Bay, all while learning about local ecology and history.

This moderately-paced ride will cover a 10 mile section of the Back Bay Loop trail over the course of 2 and a half hours. We will remain on the paved portion of the trail and will have interpretative stops along the way.

Participants must provide their own bike and helmet. E-bikes are welcome. Please note that the pace and talking points are geared towards individuals aged 14 and up. Minors must have a parent/guardian present at all times.

Distance: 10 miles
Elevation Change: 155 feet

Advance registration required. The parking and program are free. Rain or adverse weather will cancel the event.

Visit Red Rock Wilderness, part of OC Parks’ Irvine Ranch Open Space, and explore OC Parks’ newest trails!

This slow-paced hike offers an approachable experience for all skill levels to embrace their senses and explore the local flora and fauna. The hike will cover 3 to 4.5 miles with elevation gain. Hike through a variety of habitats then up a single-track trail with switchbacks and elevation gain to different overlook points with a spectacular view of Orange County.